Add web-target cookbook for configuring vulnerable web apps

[Delivers #43488585]

Note: Currently this relies on [Websploit-Tests](https://github.com/rapid7/Websploit-Tests) repository, which is a private Rapid7 repo.  Unless the repo is open-sourced, using the `web-target` cookbook will fail.  You can comment out the `websploit-tests` line in the default recipe if you want to use this without access to Websploit-Tests.

Note #2:  I replaced a few embedded opscode cookbooks with git submodules.  You may need to execute `git submodule update --init` after checking out this branch.